1. Field of the Invention
This invention relates generally to the field of sterilizing and destroying the hypodermic needle component of a syringe so as to render it safe for disposal. This invention relates specifically to a self-contained apparatus which vaporizes and sterilizes the hypodermic needle component of the syringe by passing electricity continuously along portions of the needle component until significantly all of the needle portion has been burned due to the heat produced by the electrical resistance through the needle component, with the resistance heat also sterilizing any remaining portions of the needle component.
2. Prior Art
Current medical practice favors one-time use hypodermic needle syringes over reuseable syringes. After a one-time use hypodermic needle syringe has been used, it must be disposed of properly. A used hypodermic needle syringe often poses a health hazard to any person coming into contact with a contaminated needle or syringe. The widespread exposure of contagious and fatal diseases multiplies this danger.
The most common method for disposing of used hypodermic needle syringes is a "sharps" container. A sharp's container merely is a plastic container into which the used hypodermic needle syringes are placed. When the container is full, a cap is placed on the container and the container is disposed of. Typically, a service picks up the full sharps' containers and disposes of the full containers either through incineration or in landfills. When destroyed in incinerators, the sharps' container provides a sufficient method of disposal of the used hypodermic needle syringes. However, sharps' containers suffer from several disadvantages. First, the used hypodermic needle syringes are not sterilized before being placed in the sharps' container. This can lead to unintentional contact with a contaminated needle. Second, if the sharps' containers are disposed of in a landfill, there always is the possibility that the sharps' container can inadvertently open or be broken, thus exposing the contaminated needles.
An electrical syringe needle destroyer is disclosed in U.S. Pat. No. 4,628,269 to Ch'ing-Lung. The Ch'ing-Lung device comprises a pair of spaced apart electrodes within a self-contained unit. The needle of the syringe is inserted into an opening in the unit until the base of the needle component is positioned between the two electrodes. When electricity is passed between the electrodes, the electricity causes the portion of the needle between the electrodes to melt, thus severing the needle from the syringe body. The needle portion falls into a collection means and can be disposed. The Ch'ing-Lung device does not destroy the needle, but merely severs the needle from the syringe body. Therefore, the Ch'ing-Lung device does not eliminate the dangers of contamination from the end of the needle, nor the safety hazard obvious from having many loose needle heads in the unit.
A plastic syringe destruction device is disclosed in U.S. Pat. No. 4,860,958 to Yerman. The Yerman device employs a cylinder and piston compaction unit which uses heat to thermally smash complete plastic syringes, including the needle component, into a compacted mass. One or more plastic syringes are placed in the cylinder and the cylinder lid is closed. The syringes then are heated to temperatures between 100.degree. C. and 200.degree. C. to bring about melting of the syringes, as well as sterilization. The piston travels upwardly in the cylinder while the syringes are at temperature, thus compacting the softened or molten plastic syringes into the compacted mass. The Yerman device suffers from several disadvantages, the most important of which is that the syringes are not raised to a temperature high enough to destroy the metal needle portion of the syringe. After the plastic syringes have been compacted into a mass, the metal needles typically protrude from the plastic mass, thus still posing a danger to the operator. Although the needles may have been sterilized, puncture wounds caused by the needles are neither desired nor healthy.
A hypodermic syringe needle destroying and sterilizing apparatus and method is disclosed in U.S. Pat. No. 4,877,934 to Spinello. The Spinello device is aimed specifically at destroying the metal needle portion of the hypodermic syringe by using electrical resistance heating between electrodes. The hypodermic needle is placed in a carrier which contacts the upper portion of the metal needle closest to the syringe barrel. The carrier then carries the syringe over an upwardly sloping second electrode. As the needle point contacts the second electrode, electricity passes from the second electrode through the metal needle into the first electrode, thus causing resistance heating of the metal needle. In theory, the electrical resistance heating melts and destroys the metal needle. However, in practice, the electrical resistance heating generally only softens the metal needle such that as the metal needle contacts the upwardly sloping second electrode, the metal needle bends outward. Although the Spinello device may heat the metal needle to a temperature high enough to sterilize it, typically the metal needle remains and poses the same health and safety hazard any other sharp instrument has. Further, the Spinello device comprises many moving parts which have the potential of jamming and wearing.
A disposable needle and syringe destructor unit is disclosed in U.S. Pat. No. 4,969,379 to Taylor, et al. The Taylor device essentially is a syringe guillotine. The syringe is inserted into a receiving hole a certain distance, and a spring-biased piston is hand actuated forcing a cutting member down on the syringe. The process is repeated until the entire syringe has been cut into smaller portions, which portions fall to the bottom of the container. Obviously, the Taylor device suffers from the disadvantage that the syringe is not sterilized and the metal needle portion, although in smaller pieces, still presents a safety hazard. After the Taylor device is full of syringe portions, it must be disposed of in much the same manner as the sharps' containers.
Therefore, it can be seen that there exists a need for an apparatus for sterilizing and destroying the metal needle component of a hypodermic needle syringe. While past methods destroy a portion of the needle and may sterilize the needle, these devices do not do a complete job of destroying the entire needle component of the syringe, and the used hypodermic needle portion of the syringe is still not safe to the handler or for the environment. The present invention overcomes the disadvantages of the prior art by thoroughly burning and destroying significantly all of the needle portion of the syringe by continuously passing a sufficient amount of electricity through the needle, burning and destroying portions of the needle at a time. Any remaining needle portion, particularly the nub of the needle closest the syringe barrel, also has been heated, through electrical resistance heating, to a sufficient temperature for a sufficient period of time to sterilize any remaining needle portion. Unlike the prior art which acts upon only the base and tip of the needle, the present invention acts only on a small portion of the needle at a time, eliminating the need for the high amperages and voltages required by the prior art, and eliminating the problem of needles breaking between the base and tip and needles welding themselves to the electrodes as frequently occurs in the prior art devices.